Oracle

The format of Oracle tnsnames. ora file tnsnames of Oracle. the ora file has strict format requirements: tnsname. the ora content is an example to illustrate the hidden password weapon: the rule is as follows: The red font section, because it is the

Common data dictionaries in oracle simple classification of data dictionaries: According to the prefix, the data dictionaries are USER, ALL, and DBA respectively. here, USER _ * is about the object owned by the USER, ALL _ * is about the object that

Oracle cumulative sum // Add the values of a column in the current row to the values of the column in the previous row, that is, the cumulative sum: // Method 1: with t as (select 1 val from dual union all select 3 from dual union all select 5 from

In ORACLE, the syntax for adding, deleting, and modifying fields by using an SQL statement (alter table): alter table tablename add (column datatype [default value] [null/not null], ....); Alter table tablename modify (column datatype [default value]

Disk management-view disk information-you can regularly use the results of df-h to enter an External Log File. Then, you can use Oracle's "External table" to access this "External Log File". For example, -- Step 1: write a script to regularly import

How to unlock Oracle 1. view the currently unlocked object example: Execute select * from aa for update to lock table aa; Method 1: Query select 'alter system kill session 'through SQL ', ''' | trim (t2.sid) | ',' | trim (t2.serial #) | '''; 'from v

Oracle Study Notes (2) sqlplus username/password SQL DQL: select ***** DML: insert/update/delete DDL: create/drop/alter/truncate DCL: grant/revoke TCL: commit/rollback/savepoint select column name, expression, function, distinct, alias from table

In Linux, create and delete tablespaces and users in oracle # su-oracle $ sqlplus/nolog SQL> connect/as sysdba -- // create temporary tablespaces create temporary tablespace test_temp tempfile '/data/oracle /oradata/test/test_temp01.dbf '-- // file

Redhat linux 5 oracle install shell script #! /Bin/bashecho "download the ORACLE Installation dependency file" yum install-y compat-db pdksh sysstat screen libXp compat-libstdc ++ * yum install gcc-c ++ glibc libstdc ++ libstdc ++-devel make

The for update syntax in Oracle is purely a select statement: Oracle does not apply any locks, that is, Oracle does not have any restrictions on the data read by the select statement. At this time, another process may be modifying the data in the

Fuzzy column names are prefixed with the same columns in two or more tables in the SQL connection. Fuzzy column names are different in different clauses. The following is an example. There are two tables, respectively, departments and employees.

Oracle pre-defined several system exceptions and their causes named system exceptions cause access_0000_null undefined object CASE_NOT_FOUND CASE if the corresponding WHEN is not included, when ELSE is not set, the COLLECTION_IS_NULL set element

[Oracle]-[recyclebin] [Index]-after the index name restored by the recycle bin is modified, the index is automatically restored from the recycle bin, however, the index name is still the 26-bit icon in the recycle bin and is not changed to the

ORA-00376: file x cannot be read at this time solves the problem of data center power failure before, after restarting the database found a ORA-00376 error. Query the data file status: SQL> select file_id, online_status from dba_data_files order by 1

How to insert special characters in Oracle: & and '(Multiple Solutions) encountered a problem when importing a batch of data to Oracle today: Toad prompts you to assign a value to a custom variable AMP, at the beginning, I was wondering how data is

Oracle automatic partition oralce automatically backs up and deletes the backup export script five days ago in linux: export ORACLE_BASE =/opt/oracle --- installation PATH: export ORACLE_HOME =/opt/oracle/920 --- Product Directory: export PATH =/ora/

How to view table structure information 1. Use the user_tables view select * from user_tables where table_name = 'xxx '; SQL> desc user_tables ..................... 2. Use the pl/SQL package SQL> VARIABLE NUMBERSQL> VARIABLE lastextf NUMBERSQL>

Oracle11g changed the character set AL32UTF8 to ZHS16GBK SQL code Database character set (AL32UTF8) and Client character set (ZHS16GBK) are different. character set conversion may cause unexpected results. note: you can set the client character set

Pipelined function is a special function that returns a set type. in PL/SQL, pipeline functions can be used together with table functions and cursors to implement some complex functions. When used together with parallel processing, performance can

Deinstall oracle 11g on linux deinstall oracle 11g on linuxFrom 11gR2, oracle provide us an deinstall tool. with that now we can easily remove oracle binaries. oracle has provided us with a delete tool since oracle11gR2. Now we can easily Delete